CARD10: Transapical Left Ventricular Assist Device Implantation Using a Novel Accessory in Swine

Abstract

Background: Conventional left ventricular assist devices (LVADs) require an anastomosis of the outflow graft to the ascending aorta. We developed and tested a LVAD accessory, which combines pump in- and transaortic outflow in a dual lumen adapter, thus, allowing LVAD implantation solely via the left ventricular apex. Methods: The LVAD accessory (Fig. A) consisted of a 3D printed titanium inflow and a 12 mm outflow stent graft. The accessory in combination with a centrifugal LVAD (HeartMate 3, HM3, Abbott, USA) was implanted in 10 adult female Landrace pigs (104 ± 13 kg). A balloon catheter (14 mm Atlas Gold PTA Dilatation Catheter, BD, USA) was introduced via the left femoral artery and placed in the left ventricle. After lower partial sternotomy, pericardiotomy and fixation ring attachment, apical coring was performed in a standard fashion on the beating heart using cardiopulmonary bypass. The balloon was exteriorized, inflated in the outflow graft and both, the accessory with the attached outflow graft, were pulled into the left ventricle and the aorta. The accessory was attached to the fixation ring. The LVAD was connected and deaired, and the balloon catheter was removed. Results: After successful LVAD implantation in all animals, echocardiography revealed no signs of aortic or mitral regurgitation. In eight animals ramp testing was performed. The HM3 flow estimate increased from 3.7 ± 1.2 L/min at 4’500 rpm to 5.4 ± 1.2 L/min at 7’200 rpm (Fig. B). Post-mortem examination (Fig. C) revealed correct placement of the LVAD accessory with the inflow in the left ventricle (blue arrow) and the outflow graft across the aortic valve (yellow arrow). There were neither signs of damage of the aortic (*) or mitral valve (+) nor signs of thrombosis. Conclusion: The novel accessory in combination with a centrifugal LVAD allowed safe and less-invasive LVAD implantation. Ramp testing revealed effective left ventricular support in the acute swine model. Further testing in a chronic heart failure model will be performed to validate these results.